Apparatus for welding



y 1937- J. H. HOLAN. JR 2,079,857

APPARATUS FOR WELDING Filed Feb. 17. 19:55 3' Sheets-Sheet 1 I N VENTOR.

BY WW 6w, XMjQ ATTORNEYS.

May 11, 1937. HOLAN. JR 2,079,857

APPARATUS FOR WELDING Filed Feb. 17. 19 36 3 Sheets-Sheet 2 I N VEN TOR.

ATTOR May 11, 1937; J. H. HOLAN, JR 2,079,357

" APPARATUS Fbn WELDING Filed Feb; 17-, 1936 3 Sheets-Sheet 3 INVENTOR.

ATTO E Patented May 11, 1937 2,0795857 S PATENT OFFICE 2,079,857 r lAPPARATUS ron WELDING James H. Hoian, .112. Lakewood, OhioApplicationFebruary 17,1936, Serial No. 64,284 1 Claim. (Cl. 219 -4 Thisinvention relates to welding apparatus by means of which the'electrodespossess univerand particularly to that type which is used for sality ofmovement with reference to each other heavy duty welding in factoriesand in field work. and also possess a range of movement that per- Thereis a wide field of application for heavy mits welding to be accomplishedover a wide area 5 duty welding of sheet metal forms, but so faras forany setting of the apparatus.

I am aware the only apparatus, which has been A iiirther additionalobject of my invention used satisfactorily on heavy duty assembly work,is to provide an' apparatus which will enable has comprised a machine towhich it has been two parts to be riveted together withoutrequirnecessary to bring the work. The .type to which ing the rivet tobe preheated, and without necesl0 I have referred on which the work ismounted is sitating a large free area in the vicinity of the heldstationary while the other electrode is rivet for tool manipulation. Inthis connection, pressed against the work while the current is myinvention includes a device, which will cause flowing therethrough.Accordingly, in the fabthe flow of suillcient electrical current throughrication of many articles, such as sheet metal the rivet to soften theend of it so that a head vehicle bodies or railroad cars, it has beennecescan be formed merely by hand pressure of the l5 sary to secure thelarge coacting parts together, electrode against the rivet. Considerablediffleither by rivets, or by bolts. culty has heretofore beenexperienced in welding Heretofore a portable welding apparatus has'metallic sheets .to metal c ubes. pa ticularly comprised a c-shapedframe which has carried Where the tubes obtain a considerable length and9 a stationary electrode and also a movable elecwhere theyare curvedsuch as in the frame work trode, the movable electrode being operated'byof the motor vehicle body or of a railroad pasa fluid actuated piston.The chief objection to Senger car.' The shape and length of the tubessuch form of apparatus has been that it is exhave prohibited theinsertion of an electrode into I emely heavy in weight and bulky insize, and the tubes, and so it has been necessary to fasten that it isonly adapted for welding where the the plates to the tubes-either bybolts v t 25 frame can extend around thework. In assemalthou h weldingwould be g e y p r bling a motor vehicle, therefore, it has been nec- Anadditional object of my invention, therefore, I essary to drill holes inthe coacting parts and is to construct a welding apparatus, which is 1then connect them by bolts or rivets. This is capable of-welding platesto tubes without neces- UNITED STATE particularly true in makingconnections between sitating the insertion of an electrode within the 30the side and roof sheets. tube.

Where rivets are used for connecting metallic In t e dr w s, 1 rep n anp plates or forms together, it has been necessary ratus which is made inaccordance with my into preheat the rivets and then to upset them aftervention, as bein used for W i together the they have been inserted inthe rivet holes. This pa ts of a motor vehicle body; Fig. 2 is "asection procedure is not only expensive, but is objectiontaken ontheline 2-2 in Fig. 1 and on a able, for it is very diiflcult to upset arivet unless larger than that shown in Fig- 3 S an operator hassuilicient room to swing the hantion taken on the l 3- in 8- 4 a die ofa hammer in a circular-path during the wiring diagram; Fig. 5- is an endview of the upsetting operation. Furthermore, there is altransformerthat is mounted up an Overhead 40 ways the difiiculty of obtaining atight connectrackway; Fig. 6 is a section taken on the line tionwhenever the rivet is not heated to the proper 6'-6 in Fig. 5; Fig. 7 isa sectional view through e ea modified form of electrode to sho w theuse in An object of my invention is to provide an apconnection with theup-setting of a rivet; Fig. 8

paraius by means of which articles may be fab-' is .a diagrammatic view,illustrating, the use of ricated substantially entirely by spot weldingmy invention to welding a plate to a curved tube; without necessitatingthe use of the heavy frame Fig. 9 is a section on an enlarged scalethrough that carries the two electrodes. The invention the plate andtube, taken on the line 9-4 in includes an arrangement by means of whichan Fig. 8; Fig. 10 is a view illustrating means foroperator may be ableto eifect the flow of curholding the lexible conductors in predetermined50 rent through parts that are difilcult of access, spaced position; andFig. 11 is an enlarged plan and yet to obtain suflicient mechanicalstrength view of one of the spacers that are removed from in theunited'parts to withstand the stresses to the welding apparatus. whichthey are subjected while in use. The apparatus, as illustrated in Fig. 1com- An additional object is to provide an apparatus prises twoelectrodes Ill and Ii, each of which 55,

more, each may be moved universally with ref-' erence to thetransformer. The length of the conductors is dependent upon the task forwhich they are designed to be used, and the location of the transformerwith reference to the work is also determined in accordance with thefacilities at the placeof use; the arrangement shown-in Fig. 1 beingmerely illustrative of one form which the invention takes.

In Fig. 1, the transformer is supported upona carriage 2., the wheels Iiof which are adapted to travel on an overhead trackway 22. The primaryleads of the transformer are indicated at 25, as extending to a suitablewall outlet (not shown) and as having sufficient length to'allow thenecessary travel of the carriage.

The flow of current from one electrode to the work and thence to theother electrode is controlled by one of' the operators, preferably bymeans of a controller that is positioned within reach of the operatorwho is holding one of the electrodes. For convenience, the controller isindicated at II, as comprising a push button switch that is mounted onthe handle 48 for the electrode I0. Normally, the switch is held open byaspring, but is adapted when operated, to close the circuit through arelay 2!, which in turn closesthecircuitintheprimarycoil ofthetransformer. The conductors for the switch are shown at II, as beingattached to one of the secondary leads from the transformer.

- To use the apparatus, one operator presses the electrode" against oneof the plats to be' welded, such as that indicated at 35 in Fig. 2,while another operator places the electrode ,II against the plate 36.While the electrodes are incontact with the work, one of the operatorscloses the switch II and holds it closed so long as he desires tomaintain a flow of current through the work, the character and timevarying in size with the material being welded. In Fig. l, the plate 36comprises the side wall of the body of the motor vehicle while the plate35 comprises the inside wall of the tray 38.

It is desirable for some classes of work, that the electrode ill beplaced within the confines of the electrode H, and so to allow areasonable misalignment of the axes of the electrodes, the contactor IIis illustrated as a square plate while the contacting face of theelectrode ll may comprise the narrow end of a truncated cone. I havefound that satisfactory results may be obtained in welding sheet metalof at least 12' gauge by using current at approximately l8-volts and200-amperes, with a contacting face on the electrode H! of approximatelyone-eighth inch in diameter and the contacting face on the electrode llof approximately four inches square. These dimensions may be varied tosuit any particular requirement, but I have found that for blindwelding, the operator on each side of the work can move the electrodesprogressively along the parts to be welded at regular estimateddistances without necessitating marking of the work in advance. Ifdesired, the plate may be made larger, the limit being a size which canbe handled conveniently by an operator.

I have found that it is desirable to use a small the transformer.

some

. cable for the flexible conductor in order to assure a circulatingcurrent of water, the cables can be used indefinitely without danger ofburning.

A suitable water cooling system which I have found to be satisfactorycomprises conducting water from a service line 40. through a flexibleconduit II to the transformer and thence downwardly through one of thesecondary leads, thence back to the'transformer, from whence it may beconducted down the other conductor and back to From the transformer, aconduit 45 extends to a drain 6. In Fig. 6, the water passageway fromthe transformer to the flexible conduit is illustrated at 55, therebeing a tube 56 which leads from the eway into the flexible conductor.Similarly, a tube 41 connects the free end of the conductor to the rigidtube ll, the return conduit 4! having communication with the tube 48through the elbow 50. The same arrangement of parts is used for coolingeach conductor. The tube ll is preferably a rigid member, which not onlyacts as a conductor of current from the cable to the electrode, but alsoserves as a handle by means of which an operator may force the electrodeagainst the work during the welding operation.

To facilitate the posage of water along the flexible conductors, Iprefer to utilize strands that are twisted in the form of a cable and tosheathe the cable in a hose,- the internal diameter of which is largerthan the external diameter of the cable. This will allow the coolingliquid to flow through the cable and also along the outer surface of itthereby resulting in the highest efllciency of operation. The connectionadjacent the transformer may comprise a spacing sleeve ll around whichthe hose is held by a clamp II. The sleeve 80 may comprise an extension'of the terminal II, which in turn is suitably fastened by securingmembers "to a transformer terminal 9l. The. connection at the electrodeend of the cable may comprise a sleeve 84 which is rigidly attached, asby brazlng, to a cable and which has an opening through which a tube 41extends. A union nut l5 bears against a flange 86 on the sleeve andcooperates with the threaded portion on the tube 48 to lock the sleeveand tube together. The electrode end of the hose I5 is then clamped tothe sleeve in any suitable way.

In the wiring diagram of Fig. 4, the primary coil of the transformer isindicated at P and the secondary at S. The secondary leads I! and II areconnected to the electrodes, but the flow of current to the secondaryis-controlled by the hand-operated circuit controller 30, the leads 3|of which are connected to the primary side of the coil in advance of acircuit breaker indicated in general at 28. To this end, a relay 2! isshown as being connected in the circuit formed by the leads ii, and asbeing arranged to actuate the breaker 20 so as to close the circuit tothe primary coil of the transformer whenever the switch ll is closed.When pressure on the switch I. is released a spring 21 automaticallyopens the controller circuit wheneverthe current in the relay in'afurnace and without necessitating a hammer for producing the upsettingoperation. My apparatus can therefore be used for making a rivetedjoint. in those locations where a rivet may be desired. V

To accomplish such purpose, the apparatus remains the same, but theshapeof the electrodes is preferably changed. For example, in Fig. 7,

each electrode is shown as; having a cup-shaped end for receiving oneend of the rivet. In ,practice, the cold rivet is inserted through theholes in the parts to be welded, the electrode II .is placed against thehead of the rivet and the elec- 'trode I is placed against the shank.The switch is 'then' closed and is held closed until the heat developedsoftens the rivet; then, while the current is flowing, the operatorpushes the electrode against .the rivet and thereby molds the ends of itinto a head. This operation can be accomplished in a few seconds withsatisfactory results. I have found that not only is the rivet welded tothe platesbut that the plates are likewise welded to each other;

I have found, in using current in the amount that is necessary forcommercial welding. that if the flexible conductors are allowed to gettoo close together, even though they are electrically insulated thatthey are quickly burned. I believe that the difficulty is caused byinduction currents that exists around the cables while the current isflowing through them. I have found, however, that the difficulty can beovercome by taking precaution to keep the conductors out of closeproximity to each other while the apparatus is in use. To this end, thesecondary terminals 90 and 9| from the transformer are preferably spacedas far apart as possible, and care is exercised to maintain theflexible" conductors separated by a distance that is at least equal tothat between the secondary leads. I have found that a transformer whichis capable of producing a welding current of ZOO-amperes at 18-voitswill give satisfactory results if the secondary terminals are spacedapart approximately eight inches.

To assure a proper spacing of the flexible conductors, I may utilizespaced members I III which extend between the conductors, but whichpreferably are adjustable, and are also readily detachable therefrom;Each member has a telescopic body and has a'forked head at each end,which may be clamped to a forked head I I l which may be clamped-aroundthe conductor, the body portion is preferably made of an electricalnonconductor, such as a phenolic condensation product.

, My invention is particularly well adapted for welding sheets of metalto tubes of metal without requiring an electrode to be placed inside thetube. For example, in Fig. 8, I have illustrated a sheet, at I00, inposition for welding to a tube II in which one electrode I0 is placedagainst the outer surface of the plate, while the electrode H is placedagainst the outer surface of the tube. Current is then applied and aweld is made in the same manner as that heretofore described. When theelectrode I0 is placed on the sheet, the weld takes place in a spot,whereas when the position of the electrodes is reversed, the weld takesplace on a line. I have found that sheets may be welded to a tube in hismanner by holding one elecrode against the tube until the first spot iswelded and then moving the electrode ID to succeeding spots, as shown bythe broken lines Ilia in Fig. 8, while maintaining the electrode llstationary. For light work, it is not necessary therefore, to keep theelectrode ID within the confines of the electrode H. In fact, wherethe'work is sufficiently light, I may clamp one of the electrodes to oneof the members to be welded, and then move the other electrode along theother member to be welded. This, therefore, necessitates the use of onlyone man for welding.

From the foregoing description, it .will be apparent that the twoelectrodes possess universality of movement with reference to each otherand that they are therefore, capable of being work and without requiringan air hammer forv upsetting the-end of the rivet.

I claim:

A portable electrical welding apparatus comprising in combination atransformer, two .flexible current carrying cables extending from thetransformer, a rigid hollow electrode attached to the end of each cable,each cable "having a fluid conducting passageway communicating with thehollow portion of one of the electrodes, and each electrode comprising ahandle of such size that it may be grasped by an operator and thrustendwise against the work for imparting pressure thereagainst during thewelding operation, each electrodebeing movable with relation to theworkand independently of the other electrode, and each having a workcontacting area that is different in size from the other, and asource ofcurrent supply for the transformer.

JAMES H. HOLAN, JR.

